Device for gasification of solid fuels

ABSTRACT

A vessel into which a solid fuel and an oxidant are introduced to be gasified therein and from which gasified fuel is discharged, has a bottom portion including a conical chamber communicating with a tubular port. A body of liquid medium is accommodated in the conical chamber and slag produced during the gasification is being entrapped therein. A tubular member has two tubular portions, one of which is accommodated in the tubular port and the other one of which is inclined with respect to the first-mentioned portion, extends into the chamber and is provided with openings connecting the interior of the tubular member with the chamber. The tubular member is driven to rotate about the axis of the port so that the second-mentioned portion cooperates with the interior surface of the chamber to comminute the slag lumps contained in the chamber. A grinding insert is rigidly attached to the port and projects into the chamber so as to enhance the comminuting process. A wear insert is removably attached to the interior wall of the chamber, and the edges of the openings are configurated as crushing portions, so that the comminuting process is further enhanced.

United States Patent [1 1 l-laverkamp DEVICE FOR GASlFlCATlON OF SOLID FUELS [75] Inventor: Wilhelm Haverkamp, Essen,

Germany [73] Assignee: Heinrich Koppers GmbH, Essen,

Germany [22] Filed: Oct. 17, 1973 21 Appl, No.: 407,255

[30] Foreign Application Priority Data Nov. l4, I972 Germany 2255694 [52] US. Cl. 48/73; 48/76; 48/77; 48/69; ll0/l65 R; 24l/46.l7; 24l/9l [5|] Int. Cl. ClOj 3/20 [58] Field of Search 202/253; 48/63, 69, 89,

48/95, 107, DlG.2, 202, 206, 2l5, 73, 87, 77, 76; 110/28 M, 28 D, 28 P, 28 Q, 28 W, 28 Y, 165 R, l70; 24l/27, 46 R, 4615, 46.l7, 9l,

1 1 May 13, 1975 Primary ExaminerS. Leon Bashore Assistant Examiner-Peter F. Kratz Attorney, Agent, or Firm-Michael S. Striker [57] ABSTRACT A vessel into which a solid fuel and an oxidant are in troduced to be gasified therein and from which gasified fuel is discharged, has a bottom portion including a conical chamber communicating with a tubular port. A body ofliquid medium is accommodated in the conical chamber and slag produced during the gasification is being entrapped therein. A tubular member has two tubular portions, one of which is accommodated in the tubular port and the other one of which is inclined with respect to the first-mentioned portion, extends into the chamber and is provided with openings connecting the interior of the tubular member with the chamber. The tubular member is driven to rotate about the axis of the port so that the secondmentioned portion cooperates with the interior surface of the chamber to comminute the slag lumps contained in the chamber. A grinding insert is rigidly attached to the port and projects into the chamber so as to enhance the comminuting process, A wear insert is removably attached to the interior wall of the chamber, and the edges of the openings are configurated as crushing portions, so that the comminuting process is further enhanced.

9 Claims, 3 Drawing Figures PATENTED HAY I 3W5 SHEET 3 OF 3 The present invention relates to an arrangement for comminuting slag lumps or similar bodies. Such an ar rangeincnt is particularly suitable for use in a device for gasifying solid fuels in a gasifying vessel into which solids to be gasilied are introduced together with an oxidantt and from which gasified fuel is discharged, the solidifiable byproducts of the gasification process being entrapped in a body of liquid medium contained in the vessel to be discharged therefrom. The arrangement is particularly suitable for use in connection with gasifying vessels working at supcratmosphcric pressures.

It is already known to gasify solid fuels in gasifying vessels at various temperatures and under various pressures. Depending on the particular temperature used in such gasifying vessel. the ashes which are a byproduct of the gasifying process may occur in solid form or in form of liquid slag. It is also already known to provide a body of liquid medium in such a vessel. in which medium the ashes are being entrapped. Preferably. the body of liquid medium is provided in the lowermost portion of the vessel so that the solid or liquid byproduets of the gasifying process advance toward and into the body of liquid medium due to their relatively high specific weight. As the ashes enter the liquid medium. they are being rapidly cooled. which results in the formation of slag lumps of various sizes. While it is relatively easy to remove small si7c slag particles or lumps from the vessel. the removal of oversize lumps often presents a variety of problems. These problems are particularly pronounced ifthe gasifying vessel operates under superatmospherie pressure of, for instance. 30 atmospheres, since then the slag which is to be discharged from the vessel has to pass through a system of locks preventing undesirable escape of the liquid medium or of the gasified fuel from the vessel through the discharge opening for the slag. If such is the case, the large lumps. if permitted to enter the lock system. would be likely to damage or clog the lock system, or render the same inoperative.

SUMMARY ()I" 'IHF. INVENTION Accordingly, it is an object of the present invention to avoid the drawbacks of the prior art gasifying devices.

More particularly, it is an object ofthc present invention to prevent oversize lumps from entering the slag discharge opening of the gasifying device.

It is a further object of the present invention to provide. in a gasit'ying device, an arrangement for comminuting the slag lumps prior to their discharge through the slag discharge opening.

In pursuance of the above objects and others which will become apparent hereinafter. one feature of the invention resides in providing the gasifying vessel with a bottom portion converging toward the discharge opening which is coiifiguratcd as a tubular port. A body of liquid IIlL'(lIl|IIl is accommodated in the converging bottom portion, and a tubular member having two pot tioiis which are inclined will! respect to one another is 'sIlltHlttl iii the legion of the bottom portion so that one of the portions of the tubular member is coaxially ac toininotlatctl in the tubular port and the other one of till the tubular portions projects into the vessel. The firstmcntioned portion of the tubular member is connected to drive means rotating the tubular member about the axis of the tubular port. and the second-mentioned portion of the tubular member is provided with a plurality of apertures connecting the interior of the tubular rmember with the interior of the vessel.

According to a currently preferred embodiment of the invention. the apertures are slots extending axially of the second-mentioned portion. and the axially extending edges of the slots maybe configurated as crushing portions.

Experience has shown that it is also advantageous to enhance the comminuting process by providing a grinding insert which is rigidly attached to the bottom portion of the vessel so as not to share the rotational movement of the tubular member. at least portions of the grinding insert projecting into the bottom portion of the vessel so that the rotating tubular member cooperates with the grinding insert in diminishing the size of the slag lumps.

Since the comminuting process takes place between the interior surface ofthe stationary bottom portion of the vessel and the rotating tubular member. it is advantageous, according to still another feature of the invention, to removably attach at least one wear insert to the aforementioned surface so as to eliminate or at least reduce the wear thereof and to be able to exchange the wear insert after it has been worn off.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims The invention itself. however. both as to its construction and its method of operation. together with additional objects and advantages thereof. will be best understood from the following description of specific embodiments when read in conncetion with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a partially sectioned side elevational view of the gasifying device with the associated slag discharge and conveyance arrangements;

FIG. 2 is a sectional view of the bottom portion of the vessel of the gasifying device showing the arrangement according to the invention; and

FIG. 3 is a cross-sectional view taken on line III-Ill of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. I ofthe drawing illustrates a device for gasil'ication of solid fuels. comprising a gasification vessel I and a burner 2 situated at the inlet end k in the draw ing the upper end i of the vessel I. The solid fuel to be gasit'ied. such as coal dust or similar particulate substances. and the oxidizer. such as pure oxygen or air which may be enriched with oxygen and which also may contain water vapor or steam. are delivered to the burner 2 through the conduits 3 and 4. The solid fuel which has been gasil'ied in the interior of the vessel I leaves the same through the discharge conduit 5. while the solid or liquid byproducts of the gasification process which will be called slag throughout the specification are being entrapped in a body of liquid inedinin 6 contained in the bottom portion 7 of the vessel I. It is to be iioled in this connection that the higher specific weight of the slag. when compared with the specific weight of the gasified fuel. in itself causes the slag particles to proceed toward the body of liquid medium 6. However. it is also concei ablev and well known in the art. to provide at least one di erting baiile (not shown; in the vessel so that the gasified fuel con taining slag particles is forced to flow around the baffle and close to the surface of the body of liquid medium 6 so that the inertial force of the particles enhances the entrapment process Once the solid or liquid slag enters the body of liquid medium 6, it is being rapidly cooled by the latter with attendant formation of granules most of which are of relatively small size. However. the process of formation of these slag granules or lumps is largely uncontrollable and even unpredictable. so that a small portion of the slag conglomerates into relatively large-size lumps. It may be readily understood that if such oversize lumps are left unchecked. they may eventually clog a slag discharge conduit 8 of the vessel 1 and/or damage the same To avoid this possibility. a comminuting arrange ment is provided in the vicinity of the slag discharge conduit 8, which arrangement will be described in greater detail later. and which reduces the size of the oversized lumps by disintegrating the same. and the thus comminuted slag is then discharged from the \esse] 1 through the slag discharge conduit 8. After passing through the conduit 8, the slag enters a lock container 9 which is indispensable if the pressure in the vessel 1 is superatmospheric and is forwarded from the latter to a discharge conveyor 10 or a similar slagremoving unit.

Prior to describing the comminuting assembly in greater detail. the slag discharge procedure will be discussed. lfthe lock container 9 is provided which will always be the case if the pressure inside the vessel 1 dif fers from the pressure outside the same. then the discharge of the slag from the bottom portion 7 is con' ducted on a substantially continuous basis. in order to achieve this. a valve 11 is provided downstream of the lock container 9 and a valve 12 is provided upstream of the same. For the discharge of the slag to be continuous. the valve 12 is open most of the time. except for brief periods of time during which the valve 11 is open. Namely. while the valve 12 is open and the valve 11 closed. the pressure inside the lock container approximates that inside the vessel and. since the valve 12 is open. the slag particles are permitted to enter the interior of the loci: container 9 and to accumulate therein. After a certain period of time. corresponding to a certain amount of slag particles being accumulated in the lock container 9. the valve 12 is closed and the valve 11 opened. resulting in a drop of the pressure inside the lock container 9 to the ambient pressure. and in attendant discharge of the contents of the lock container 9 through the valve 1]. Once the lock container 9 is empty. the valve 11 is closed and valve 12 opened. so that the slag particles are again allowed to enter the lock container 9. However. it is also conceivable that the operation of the discharge assembly 9. l]. 12 could be intermittent if so desired. If such were the case. the valve 12 would be closed for most of the time so that the slag particles would accumulate in the bottom portion 7 upstream of the valve 12. When the amount of slag accumulated in the bottom portion 7 reaches a predetermined value. the valve 12 is opened while the valve 11 is closed. and the afore-described process ensues with one exception. namely that the valve 12 remains closed until a sufficient amount of slag is accumulated in the bottom portion 7.

Referring now to FIG. 2 of the drawing. it may be seen therein that the bottom portion 7 of the vessel 1 comprises a circumferential wall 15 which defines a chamber 14 conically com erging in the direction toward the slag discharge conduit 8 (compare FIG. 11. The comminuting assembly includes a tubular member 13 which has a first tubular portion 13a extending into the chamber 14 and a second tubular portion 13b which is coaxial with the chamber 14. The first portion 13a is inclined with respect to the second portion 13b of the tubular member 13 so that it encloses a first acute angle with the axis of the chamber 14. while the generatrices of the conical surface surrounding the chamber 14 enclose a second acute angle with the same axis. While it is conceivable that these two angles could be of equal magnitude. experience has shown that it is advantageous if'the second acute angle is larger than the first one. Preferably. the inner surface of the cir cumferential wall 15 is provided with a removable lining or wear insert 16. When the tubular member 13 is caused to rotate in a manner which will be described later. the portion 13a orbits about the axis of the chamber 14 in a circular path. and two positions of the portion 13a in this path are illustrated in FIG. 2 in full and dash-dotted lines. namely the positions lying in the plane of vertical section of the bottom portion 7 of the vessel 1. It is evident that if any oversize lump of slag enters or is caused to enter between the rotating portion 131: and the wear insert 16. the cooperation of the portion 130 and the insert 16 disintegrates the slag. This process is further enhanced if a grinding insert 17 is located in the vicinity of the lower end of the chamber 14. ln that event. the grinding insert 17 cooperates with the portion 13a and the wear insert 16 in comminuting the slag lumps.

While it is possible that the tubular circumferential wall of the portion 13a could be uninterrupted. it is currently preferred. in accordance with a further embodiment of the invention. to provide at least one slot 18 extending axially of the tubular portion 1321 through the circumferential wall thereof thus establishing communication between the interior of the tubular element 13 and the chamber 14. the width of the slot 18 corre sponding to the size of the slag particles which can safely proceed toward the slag discharge conduit 8. Adantageously the axially extending edges of the slot 18 are configurated as crushing portions 19. If such crushing portions are provided. the effectiveness of the comminuting process is further improved.

A worm wheel 20 is rigidly attached to the portion 13b of the tubular member 13 so as to share its rotational movement about the axis of the chamber 14. A worm gear 21 is mounted on a drive shaft 22 (see FIG. 3 l which passes through a water-tight packing 23. A reversible drive motor 24 whose direction of rotation may be reversed if the tubular member 13 becomes jammed is connected to the drive shaft 22 via an overload clutch 25 of conventional design. While this dri\ e means is particularly suitable for use in the device of the above kind. it is by no means critical for the invention. and it is to be understood that any other conventional drive means could be used instead.

In the illustrated embodiment. the bottom portion 7 and the slag discharge conduit are interconnected by means of a port. which ha been in general assigned a mnneral 29. 'l'he port 1) is substantially tubular and preferably coaxial with both the chamber l-lot'lhe bottom portion 7 ol' the vessel l and the slag discharge conduit 8. lhc portion Uholthe tubular member is aceonunodated within this port 2). as are the worm gears and II, and at least a portion of the grinding insert [7. The portion [3b is supported by self-aligning bearings 26. or. alternately, journal or similar bearings. Advantageously, the bearings 26 are themselves resiliently mounted in the port 29 by means of rubber, spring or similar resilient elements 27. The purpose of these resilient elements 27 is to resiliently counteract the jolting forces generated during the comminuting process.

ln devices of this kind, it is particularly important to prevent the solid-containing liquid medium from entering the hearings or similar relatively sensitive parts, since the presence of solid contaminants in the liquid medium would otherwise result in damage to those sensitive parts. In order to avoid this possibility, there are provided blocking liquid conduits 28 leading into the port 29 and particularly into the clearance between the port 29 and the tubular member 13.

While the above-described arrangement has been conceived for the purpose of comminuting slag particles or lumps, experience has shown that there is an additional advantage which may be obtained by using this particular arrangement. Namely, since the tubular member [3 is in continuous rotation, it not only comminutes already formed oversize slag lumps, but also to a certain extent prevents their formation. This can be explained by the fact that, due to the continuous rotation of the member 13, the slag deposit in the chamber 14 is in steady motion, and the otherwise likely possibility of forming connections between individual slag particles. resulting in formation of oversize lumps, is at least lessened.

The arrangement according to the invention is particularly useful if utilized in connection with a solid fuel gasifying device, and it has been disclosed in this connection. However, it is evident that the field of possible use of this comminuting arrangement is not limited to this particular area. It is to be understood that the afore-described comminuting arrangement may also be used in devices of different kinds in which relatively bulky particles are being formed in or are being deposited by a fluid medium. One of the possible applications of this device would be in the field of air or water pollution, particularly if the contaminants have a tendency to form relatively bulky lumps or conglomerates.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of gasifying devices differing from the types described above.

While the invention has been illustrated and described as embodied in a gasifying device, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can. by applying current knowledge readily, adapt it for various applications without omitting features that. from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims:

I. In a device for gasil'ying solid fuels, a combination comprising an upright vessel including an upper portion having an inlet for admission of solid fuel to be gasified and of an oxidant, a burner in said inlet, an outlet for discharging gasificd fuel, and a bottom portion below said upper portion and having an interior surface circumferentially forming a downwardly conically converging bottom chambcr having an axis and containing a liquid medium for entrapping slag formed in said upper portion during the gasification of the solid fuel; a tubular port downwardly of and coaxially merging with said bottom chamber and communicating therewith; comminuting means including a tubular member having a first portion accommodated in and coaxial with said tubular port, and a second portion inclined with respect to said first portion and situated in said bottom chamber proximate to said interior surface thereof and defining therewith a comminuting gap, said second portion being provided with at least one aperture connecting the interior of said tubular member with said bottom chamber for discharging slag particles below a predetermined size from said bottom chamber, and drive means for rotating said tubular member about the axis of said first portion thereof so that said second portion conically orbits about said axis with attendant orbiting of said comminuting gap, and cooperates with said interior surface to comminute the slag in said bottom chamber to said predetermined size.

2. A combination as defined in claim 1, wherein the generatrices of said interior surface enclose an acute angle with the axis of said bottom chamber which is larger than an acute angle which is included between said second portion and said axis of said bottom chamber.

3. A combination as defined in claim 1, wherein said at least one aperture is an elongated slot extending axially of said second tubular portion.

4. A combination as defined in claim 1, further comprising a grinding insert accommodated in and rigidly connected to said bottom portion of said vessel; and wherein said tubular member cooperates with said grinding insert so as to comminute the slag contained in said bottom portion.

5. A combination as defined in claim 1, further comprising a grinding insert accommodated in and rigidly connected to said tubular port and at least partially projecting into said bottom chamber; and wherein said tubular member cooperates with said interior surface and said grinding insert so as to comminute the slag contained in said bottom chamber.

6. A combination as defined in claim 1, further comprising at least one wear insert removably attached to said interior surface of said bottom chamber; and wherein said tubular member cooperates with said wear insert so as to comminute the slag contained in said bottom chamber.

7. A combination as defined in claim 1. wherein said second portion further comprises a plurality of crush ing portions extending radially outwardly of said second tubular portion.

8. A combination as defined in claim 1. said tubular member further comprising a plurality of aperture means extending axially of said second portion of said tubular member and connecting thc intcriur (if said tuhular member with the interior of said l'mtlum chumbcr and a pluruiity (if crushing portions extending rudially outwardly. of said second purtiunv 9. A combination as defined in claim 8, wherein said rutcd as said crushing purtinns.

x x a x z 

1. IN A DEVICE FOR GASIFYING SOLID FUELS, A COMBINATION COMPRISING AN UPRIGHT VESSEL INCLUDING AN UPPER PORTION HAVING AN INLET FOR ADMISSION OF SAID FUEL TO BE GASIFIED AND OF AN OXIDANT, A BURNER IN SAID INLET, AN OUTLET FOR DISCHARGING GASIFIED FUEL, AND A BOTTOM PORTION BELOW SAID UPPER PORTION AND HAVING AN INTERIOR SURFACE CIRCUMFERENTIALLY FORMING A DOWNWARDLY CONICALLY CONVERGING BOTTOM CHAMBER HAVING AN AXIS AND CONTAINING A LIQUID MEDIUM FOR ENTRAPPING SLAG FORMED IN SAID UPPER PORTION DURING THE GASIFICATION OF THE SOLID FUEL; A TUBLAR PORT DOWNWARDLY OF AND COAXIALLY MERGING WITH SAID BOTTOM CHAMBER AND COMMUNICATING THEREWITH; COMMINUTING MEANS INCLUDING A TUBLAR MEMBER HAVING A FIRST PORTION ACCOMMODATED IN AND COAXIAL WITH SAID TUBLAR PORT, AND A SECOND PORTION INCLINED WITH RESPECT TO SAID FIRST PORTION AND SITUATED IN SAID BOTTOM CHAMBER PROXIMATE TO SAID INTERIOR SURFACE THEREOF AND DEFINING THEREWITH A COMMINUTING GAP, SAID SECOND PORTION BEING PROVIDED WITH AT LEAST ONE APERTURE CONNECTING THE INTERIOR OF SAID TUBLAR MEMBER WITH SAID BOTTOM CHAMBER FOR DISCHARGING SLAG PARTICLES BELOW A PREDETERMINED SIZE FROM SAID BOTTOM CHAMBER; AND DRIVE MEANS FOR ROTATING SAID TUBLAR MEMBER ABOUT THE AXIS OF SAID FIRST PORTION THEREOF SO THAT SAID SECOND PORTION CONICALLY ORBITS ABOUT SAID AXIS WITH ATTENDANT ORGITING OF SAID COMMINUTING GAP, AND COOPERATES WITH SAID INTERIOR SURFACE TO COMMINUTE THE SLAG IN SAID BOTTOM CHAMBER TO SAID PREDETERMINED SIZE.
 2. A combination as defined in claim 1, wherein the generatrices of said interior surface enclose an acute angle with the axis of said bottom chamber which is larger than an acute angle which is included between said second portion and said axis of said bottom chamber.
 3. A combination as defined in claim 1, wherein said at least one aperture is an elongated slot extending axially of said second tubular portion.
 4. A combination as defined in claim 1, further comprising a grinding insert accommodated in and rigidly connected to said bottom portion of said vessel; and wherein said tubular member cooperates with said grinding insert so as to comminute the slag contained in said bottom portion.
 5. A combination as defined in claim 1, further comprising a grinding insert accommodated in and rigidly connected to said tubular port and at least partially projecting into said bottom chamber; and wherein said tubular member cooperates with said interior surface and said grinding insert so as to comminute the slag contained in said bottom chamber.
 6. A combination as defined in claim 1, further comprising at least one wear insert removably attached to said interior surface of said bottom chamber; and wherein said tubular member cooperates with said wear insert so as to comminute the slag contained in said bottom chamber.
 7. A combination as defined in claim 1, wherein said second portion further comprises a plurality of crushing portions extending radially outwardly of said second tubular portion.
 8. A combination as defined in claim 1, said tubular member further comprising a plurality of aperture means extending axially of said second portion of said tubular member and connecting the interior of said tubular member with the interior of said bottom chamber, and a plurality of crushing portions extending radially outwardly of said second portion.
 9. A combination as defined in claim 8, wherein said axially extending aperture means are slots including elongated edges, and wherein said edges are configurated as said crushing portions. 